Froth flotation is one of the most widely used processes for beneficiating ores containing valuable minerals. It is especially useful for separating finely ground valuable minerals from their associated gangue or for separating valuable minerals from one another. The process is based on the affinity of suitably prepared mineral surfaces for air bubbles. In froth flotation, a froth or a foam is formed by introducing air into an agitated pulp of the finely ground ore in water containing a frothing or foaming agent. A main advantage of separation by froth flotation is that it is a relatively efficient operation at a substantially lower cost than many other processes.
It is common practice to include in the flotation process, one or more reagents called collectors or promoters that impart selective hydrophobicity to the valuable mineral that is to be separated from the other minerals. It has been suggested that the flotation separation of one mineral species from another depends upon the relative wettability of mineral surfaces by water. Many types of compounds have been suggested and used as collectors in froth flotation processes for the recoverY of metal values. Examples of such types of collectors include the xanthates, xanthate esters, dithiophosphates, dithiocarbamates, trithiocarbonates, mercaptans and thionocarbonates.
U.S. Pat. No. 3,298,520 issued to Bikales relates to the use of 2-cyanovinyldithiocarbamates which are useful as promotors in benefication of ores by froth flotation.
U.S. Pat. No. 4,372,864 issued to McCarthy relates to a reagent which is useful in the recovery of bituminous coal in froth flotation processes. The reagent of the invention comprises a liquid hydrocarbon, a reducing material and an activator material. The reducing material is phosphorus pentasulfide and the activator material is zinc ethylene bis(dithiocarbamate).
U.S. Pat. No. 4,514,293 issued to Bresson et al and U.S. Pat. No. 4,554,108 issued to Kimble et al relate to the use of N-carboxyalkyl-S-carboalkoxydithiocarbamates and carboxyalkyldithiocarbamates, respectively, as ore flotation reagents.
U.S. Pat. No. 4,595,538 issued to Kimble et al relates to the use of trialkali metal or triammonium N,N-bis(carboxyalkyl)dithiocarbamates as ore flotation depressants.
U.S. Pat. No. 3,876,550 issued to Holubec relates to lubricant compositions containing an additive combination which comprises (A) an alkylene dithiocarbamate and (B) a rust inhibitor based on a hydrocarbon-substituted succinic acid or certain derivatives thereof.
U.S. Pat. Nos. 1,726,647 and 1,736,429 issued to Cadwell relate to phenylmethylene bisdithiocarbamates and methods for preparing the same.